Texture stripes on brush.

Use smoothing groups.

https://developer.valvesoftware.com/wiki/Smoothing_groups

You probably want to use Smoothing Groups for this: https://developer.valvesoftware.com/wiki/Smoothing_groups

Select the Face Edit Tool, which brings up the Face Edit Sheet

Then, select all the faces you want to look smooth

Click on Smoothing Groups in the Face Edit Sheet

[Blocked Image: http://i.imgur.com/Z9yMXHy.jpg]

That will bring up a window with tabs numbered from 1 to 24, assign the selected faces to one of these tabs. (It doesn't matter which one)

When you compile your map, It should look smooth as a baby's butt.
Hope it helps.

Looks like those brushes don't quite line up on the grid probably like 0.01 out or something, try remaking it exactly on the grid and use the smoothing groups.

I suggest you just redo the prop. If you look closely you can see that its pretty messy (small meshes inside the brush, off the grid stuff ETC)

That brush could be made with one solid btw.

Yeah you can add faces to a brush as long as it isn't concave. So that entire piece can be made from one pieces. There should be some tutorials online for that, try interlopers.net

Its because this very top brush. Delete it and check it again.

did you make this using the vertex tool or the clip?

Can you post a map file here?

https://www.dropbox.com/s/f8uoy5q5ri0azoq/model2.vmf?dl=0

Here you go. Just add smoothing groups on it and this should work as inteded.

The problem was with this brush faces. You can't have so many faces in one brush. Hope I helped.

This is how it looks in-game with my lighting settings.

[Blocked Image: http://i.imgur.com/bt0M6k8.jpg]

I think it depends on lighting casting angle.